Sealing-in machine



1,645,991 .1. J. HIGGINS SEALING-IN MACHINE Filed July 30. 1924 INVENTORJOHN J. HIGGINS Patented Oct. 18, 1927.

UNITED STATES PATENT OFFICE.

JOHN JOSEPH HIGGINS, OF EAST ORANGE, NEW JERSEY, ASSIGNOR TOWESTINGHOUSE LAMP COMPANY, A CORPORATION OF PENNSYLVANIA.

SEALING-IN MACHINE.

Application filed July 80,

This invention relates to sealing-in machines and more particularly tomachines for sealing stems in radio bulbs and the like.

An object of the invention is to provide a simple and effective devicefor expeditiously sealing a bulb to a. mount.

Another object of the invention is to provide a sealing-in device inwhich a bulb may be sealed to a mount without rotation thereof.

A further object of the invention is to provide suitable coordinatingmachine elements for supporting a bulb on a given axial line and forproviding one or more heat zones for sealing the bulb to the mount andfor severing the waste portion from the bulb.

Other objects and advantages will be apparent as the descriptionproceeds.

Radiotrons or incandescent lamps of the character to which the presentinvention relates, have generally been produced by Sealing a bulb to amount comprising a flare tube and an exhaust tube for audio bulbs and inthe union of a bulb to a mount including a flare tube, exhaust tube andarbor for certain types of incandescent electric lamps.

The present invention may be applied to either a lamp or a radio tubebut, as hereinafter described. is illustrated with reference to thelatter.

Radio tubes as heretofore manufactured, included supporting a mount andpositioning a bulb thereover. Fires were then directed to heat the bulbabout its circumference, adjacent to the flare tube of the mount. Forthe purpose of providing a complete circumferential heated area on thetube, it was considered necessary to rotate the bulb and mount duringthe heating operation. This rotation was heretofore thought to beimportant and was practiced as a vital and necessary operation in theproduction of a sealed-in lamp or radiotron and it was the acceptedmethod to properly heiat the bulb to give the desired sealing resu t.

The rotation of the mount and bulb limited, to a considerable degree,the possible output of a sealing-in machine. The necessity of a. supportto properly hold the bulb and mount during the sealing-in makes itessential to rotate the entire sup orting structure, which bringscertain port1ons of such structure in the path of the flames dur- 1924.Serial No. 729,054.

ing rotation and obviously interrupts the heating operation. This, ofcourse, is not very vital as a detriment to the sealing-in operation,but has its disadvantages, particularly since it subjects certainportions of the structure to relatively high temperatures and causes aWarping of the parts and often results in the necessity of realigningthe bulb support to maintain the proper axial arrangement with respectto the rotating structure which in such machines is termed thesealing-in head.

Ordinarily, the inside diameter of a bulb and the outside diameter ofthe flared portion of a flare tube are of such dimensions that when theparts are in position for sealing, the space therebetween is relativelygreat.

The sealing-in operation required several steps of heating and arotation of the bulb so that the neck thereof could be shaped previousto its union with the flare tube. That is, the necking down of the bulbcould only be satisfactorily performed by a rotation of the bulb andsimultaneously heating the same in a series of stages, until it wasfinally rendered plastic and the wall collapsed to unite the neck with aflare tube.

It has been found that by providing a bulbwith a neck of but slightlygreater internal diameter than the external ortion of the flare tube.suflicient heat may e provided that the forming of the neck of the bulband its union with the mount may be effected without rotation thereof.The applicant has discovered that if the space between the perimeter ofthe flared portion of the flare tube is spaced approximately 3/16 of aninch away from the inner surface of the neck of the bulb, a good seal ispossible without the usual rotation of the work parts.

By creating a complete circular heat zone about the glass parts, it ispossible to produce a uniform and eflicient seal between the parts,after which fires, termed cutting-oil fires, are directed against thebulb just below the seal and the lower portion or cullet of the bulb issevered and the lamp bulb may be removed from the machine. Mechanism mayalso be employed for changing the relative position of the bulb andmount to stretch the seal after which the bulb may be removed.

The invention will be more fully under-' stood by reference to theaccompanying drawing, in which,

Fig. 1 is a plan view of a sealing-in device embodying the presentinvention;

Fig. 2 is a front elevational view of the device shown in Fig. 1, aportion of the burner element being broken away;

Fi 3 is an enlarged fragmenta view show ng the relative position of a bb in a supporting structure; and

Fig. 4 is an example of a radiotron bulb after the sealing-in operationhas been performed.

The invention may include a suitable supporting table having what willherein be termed a stationary sealing-in head 11 secured thereto. Thehead 11 may comprise a central post or guide 12 havin projecting arms 13and 14 to which may secured uprights or supports 15 and 16 respectively.At the upper ends of the said supports may be fastened an arcuate plate17 which carries vertical plates 18 having inclined surfaces 20 to whichtension members 19 may be suitably attached. The ends of said tensionmembers may project toward and be disposed in inclined relation to thevertical axial line of the head 11. A beveled edge 21 is provided on thearcuate plate 17 (see Fig. 3) to engage with a lower annular depressedsurface of a bulb 22, when the bulb is in position between the plates18.

A support for a stem or a mount may include a chuck or gripping device23 to secure an exhaust tube 24 of a mount which may comprise theexhaust tube 24 consolidated at a press 25 with a flare tube 26 see Fig.3), the usual electrodes are fastene to supports or leading-in,conductors 31 which are sec'ured in the press. These several parts whenunited, constitute a mount or stem. The gripping mechanism may be ofanfiesuitable character to secure the exhaust tu and maintain the mouthin axial alignment in the head. The gripping device illustrated, maycomprise a weighted member 27 slidable upon a hollow shaft 28. Sphericalgripping members 29 may be disposed in the wall of the shaft andnormally in engagement with an interiorly inclined surface 30 of themember 27. The member 27 is mounted upon the shaft 28 and the spheres 29moved toward the axial line of the shaft, by reason of the otentialenergy of the said weighted memher, to grip the exhaust tube 24 of thelamp mount when inserted into the shaft 28 and hold the mount with isaxis coincident with the axial line of the head. The leading-1nconductors 31 may be disposed along the side or wrapped about theexhaust tube when the same is inserted into the chuck.

For the pur se of efiectin a stretchm operation of t e seal when t ebulb 22 is sealed to a flare tube 26 of the mount, 1n the manner to behereinafter more fully out from apertures debers 29 when the weight isreleased. A

scribed, the shaft 28 is slidable in the guide 12 and may be disposed inengagement with a lever 32 operable by means of a chain 33 connected toa foot treadle (not shown) to reciprocate the shaft 28. The lever 32 maybe pivoted at 34 to a bracket 35 and may be normally urged intoengagement with a collar 36 secured to the shaft 28 b a spring 37.

A sto arm 38 may be provi ed to engage with t e lever 32 and limit theupward movement thereof.

Means for releasing the exhaust tube 24 after the same has moveddownwardly a predetermined distance, may comprise a anged portion 39integral with the post 12. This flanged portion is so positioned withrespect to the weighted member 27 that when the shaft 28 is moveddownwardly, for a redetermined distance, the said weighte member willengage flange 39, thus preventing further movement of the member andrelieving its engagement with the gripping-spheres 29 at which time theexhaust tube 24 will be released and the sealed-in bulb may be removedfrom the head.

A heating element for rendering the bulb and flare tube plastic is shownin the present embodiment of the invention as comprisin a pair ofconcentrically arranged manifo ds 41 and 42. The manifold 41 may receiveheat producing fuel through a feed pipe 43 having a control valve 44 andthe manifold 42 may receive fuel through a feed pipe 45 which may beprovided with a control valve 46. p

The manifolds may, as shown, he of circular form and the manifold 41 mayhave a pluralit of burner nozzles 47 arranged in radial ormation andspaced at intervals.

The nozzles 47 may be so disposed as to direct'flames 48 against thewall of a bulb 22 to soften the same and elfect a union between the walland the flared portion of a flare tube 26 (see Fig. 3). The manifold 42may be provided with nozzles 49 spaced at intervals and may bepositioned in staggered relation with respect to the nozzles 47. Thenozzles 49 are employed to sever the lower or waste portion of the bulbfrom the sealed bulb and flames 51 issuing from these nozzles are termedthe cutting-off fires. In order to facilitate the cutting-off operation,an air pipe 52 .is provided and may be connected .to a suitable pressureline to direct a current of air through the shaft 28 and 53 at the upperend thereof. The manifolds may be suitably supported in proper relationtothe sealingin head by a bracket 54.

In practice, the weighted member may be lifted and the exhaust tube of astem or mount may be inserted into the stem-holder and gripped by reasonof the spherical with the may then be placed over the stem and held inits proper relation thereto by the bulb supporting plates 18. Theburners or nozzles 47 may be lighted and controlled by means of thevalve 44. Flames of intense heat may be caused to heat the bulbcircumferentially at the point on its surface adjacent to the flaredportion of the flare tube to seal the same thereto. The valve 46 maythen be manipulated to cause flames from the nozzles 49 to sever thelower or waste portion 22' of the bulb from the sealed portion. Air maybe directed outwardly from the shaft by means of the air pipe 52 tostretch or thin out the wall of the neck and thus facilitate thesevering operation.

After the bulb has been sealed in and the cullet cut oil, a downwardpull may be applied to the chain 33, thus permitting the shaft 28 todrop thereby effecting a relative downward movement of the stem withrespect to the bulb while the seal is still plastic. This operation istermed the pulldownand is. for the purpose of relieving any strains orstresses that may be set up at the point of union during the sealingoperation. The pull-down will continue as long as the chuck grips theexhaust tube. A slight downward movement of the stem is all, however,that is necessary and as the weighted member 27 comes in contact withthe flanged portion 39, the spherical mem bers become disengaged withthe exhaust tube and the shaft 28 is permitted a slight additionaldownward movement to release the exhaust tube. The bulb is thereforeready to be removed from the head and while the shaft 28 is in its lowerposition. the exhaust tube of another mount may be inserted between thegripping members 29 and sccured thereby when the treadle is released topermit the shaft to rise and the weighted member to engage sphericalmembers.

In the present construction, a bulb may be sealed to a mount in auniform and eflicient manner and heads constructed according to thepresent invention avoid the necessity of several belts and pulleys whichhave heretofore been necessary to rotate the heads. Furthermore,mechanism for stopping the heads in given relative positions is alsoeliminated. The initial and maintenance cost of heads of the presentconstruction is also con siderably less than has generally beennecessary when employing the various machine elements requiredheretofore for rotating and stopping the sealing-in heads. It will beunderstood that although a single head is shown and described, that aplurality of such heads may be placed on a rotary or other type ofconveyor and the various operations performed during a movement of theconveyor as is common in other sealing-in machines.

Although a preferred embodiment of the invention is shown and describedherein, it is to be understood that modifications may be made hereinwithout departing from the spirit of the invention as defined by the appended claims.

\Vhat is claimed is 1. A sealing-in head comprising a support for abulb, means for securing the exhaust tube of a mount to support themount within said bulb, means for creating a continuous heat zonecircumferentially of the bulb to fuse the bulb to the mount and meansfor creating a second heat zone circumferentially of the neck of thebulb to sever the same from the bulb.

A sealing-in head comprising a support for a bulb, means for securingthe exhaust tube of a mount to support the mount within said bulb, meansfor creating a continuous heat zone circumferentially of the bulb tofuse the bulb to the mount, means for creating a second heat zonecircumferential] y of the neck of the bulb to sever the same from thebulb and means for directing a current of air against the neck of thebulb to acilitate the severing operation.

3. A sealing-in head comprising a support for a bulb, means for securingthe exhaust tube of a mount to support the mount within said bulb, meansfor creating a uniform heat zone circumferentially of the bulb to fusethe bulb to the mount, means for creating a sec 0nd heat zonecircumferentially of the neck of the bulb to sever the same from thebulb and means for changing the relative positions of the mount and bulbwhile the sealed portion is still plastic. 7

4;. A sealing-1n head comprising a support for a bulb, means forsecuring the exhaust tube of a mount to support the mount within saidbulb, means for creating a continuous heat zone circumferentially of thebulb to fuse the bulb to the mount, means for creating a second heatzone circumferentially of the neck of the bulb to sever the same fromthe bulb, means for directing a current of air against the neck of thebulb to facilitate the severing operation and means for changing therelative positions of the bulb and mount.

5. A machine for uniting a plurality of work parts such as a lamp bulband mount comprising a non-rotatable support for the bulb and mount andnon-rotatable means for creating a zone of heat about the bulb at atemperature suflicient to fuse together the said work parts.

6. A machine for uniting vitreous lamp parts suchas a bulb and mountcomprising a non-rotatable support for a bulb, non-rotatable means forholding a mount within a bulb and in a predetermined relation to thewall thereof, a non-rotatable substantially annular burner for creatinga heat zone of sufiicient intensity to fuse and unite the said lampparts. 7

7. A sealing-in machine comprising a nonrotatable support for a bulb, anon-rotatable support for retaining a mount within a bulb and inalignment with the longitudinal axis thereof, non-rotatable means forobtaining heat about the bulb at a temperature sufficient to unite thebulb and mount and means for changing the relative positions of the bulband mount while the fused and united portions are'still plastic.

8. A sealing-in machine comprising a support for a bulb, means forsupporting a mount within the bulb, a manifold disposed about said mountand bulb, a plurality of burners asiociated with said manifold forcreatin a zone of heat circumferentially of the nec of said bulb tounite the same to said mount without rotation thereof and means forcreating a heat zone circumferentially of the neck of the bulb to severthe same from the bulb.

9. A sealing-in machine comprising a support for a bulb, means forsupporting a mount within the bulb, a manifold disposed about said mountand bulb, a plurality of burners associated with said manifold forcreating a zone of heat circumferentially of the neck of said bulb tounite the same to said mount without rotation thereof, means forcreating a heat zone circumferentialllvK of the neck of the bulb tosever said nec therefrom and means for changing the relative position ofsaid mount and said bulb while their point of union -is still plastic.

10. A sealing-in machine comprising a support for a bulb, means forsecuring the exhaust tube of a mount to support the same within saidbulb, a plurality of manifolds concentrically arranged with respect tosaid supported mount and bulb, burners associated with one of saidmanifolds for directing flames to fuse the bulb and mount together andburners on another of said manifolds for directing flames to sever aportion of the neck of said bulb therefrom.

11. A sealing-in machine comprising a support for a bulb, means forsecuring the exhaust tube of a mount to support the same within saidbulb, a plurality of manifolds concentrically arranged with respect tosald supported mount and bulb, burners associated with one of saidmanifolds for directing flames to fuse the bulb and mount together,burners on another of said manifolds for directin flames to sever aportion of the neck of sai bulb therefrom and means for directing acurrent of air against the wall of said neck to facilitate the severingoperation. I

12. A sealing-in machine comprising a su port for a bulb, means forsecuring the ex aust tube of a mount to support the same within saidbulb, a plurality of manifolds concentrically arra ed with respect tosaid supported mount an bulb, burners associatxvwwmmwwmpmmasmmw 7 edwith one of said manifolds for directing flames to fuse the bulb andmount to ether, burners on another of said manifol s for directingflames to sever a portion of the neck of said bulb therefrom, means fordirecting a current of air against the wall of said neck to facilitatethe severing operation and means for chan 'ng the relative positions ofsaid mount an bulb while their point of union is still plastic.

13. A sealing-in head comprising means for supporting a bulb with itslongitudinal axis coincident with the vertical axle of the head, a chuckfor securing the exhaust tube of a mount to osition the mount with itslongitudinal axis coincident with the axial line of said head, burnersdisposed about the neck of said bulb to create a circumferential zone ofheat to unite the neck of the bulb to the mount.

14. A sealing-in head comprising means for supporting a bulb with itslon 'tudinal axis coincident with the vertical axis of the head, a chuckfor securing the exhaust tube of a mount to position the mount with itslongitudinal axis coincident with the axial line of said head, burnersdisposed about the neck of said bulb to create a circumferential zone ofheat to unite the neck of the bulb to the mount and means for creating asecond heat zone to sever a portion of the neck below the seal.

15. A sealing-in head comprising means for supporting a bulb with itslongitudinal axis coincident with the vertical axis of the head, a chuckfor securin the exhaust tube of a mount to position the mount with itslongitudinal axis coincident with the axial line of said head, burnersdisposed about the neck of said bulb to create a circumferential zone ofheat to unite theneck of the bulb to the mount, means for creating asecond heat zone to sever a portion of the neck below the seal andsmeansfor directing a current of air against the wall of the neck tofacilitate the severing operation.

16. A sealing-in head comprising means for supporting a bulb with itslongitudinal axis coincident with the vertical axls of the head, a chuckfor securin the exhaust tube of a mount to position t e mount with itslongitudinal axis coincident with the axial line of said head, burnersdisposed about the neck of said bulb to create a circumferential zone ofheat to unite the neck of the bulb to the mount, means for creatin asecond heat zone to sever a portion of t e neck below the seal, meansfor directin a current of air against the wall of the nec to facilitatethe severing operation and means for changing the relative positions ofthe mount and bul while the sealed portion is still plastic.

' 17. A sealing-in head comprising means for supporting a bulb with itslongitudinal axis coincident with the vertical axis of the head, a chuckfor securing the exhaust tube of a mount to position the mount with itslongitudinal axis coincident with the axial line of said head, burnersdisposed about the neck of said bulb to create a circumferential zone ofheat to unite the neck of the bulb to the mount. means For creating asecond heat zone to sever a portion of the neck below the seal, meansfor directing a current of air against the wall of the neck tofacilitate the severing operation, means for chan ing the relativepositions of the mount and ulb while the sealed portion is still plasticand means for releasing said exhaust tube.

18. A sealing-in device comprising a support for a mount having a flaretube,

means for non-rotatably supporting a bulb over said mount, said bulbhaving a neck with the inside diameter thereof slightly greater than thegreatest diameter of the flare tube, and burners to provide suflicientheat to cause the neck of the bulb to contact with the flare tube.

In testimony whereof, I have hereunto subscribed my name this 29th dayof July,

JOHN JOSEPH HIGGINS.

